Cushioning mechanism for door-operating devices.



l P. R. FORMAN. GUSHIONING MECHANISM FOR DOOR OPERATING D pvrcns.

APPLICATION rILnn 11.2. 1 008.

I Patented Aug 29,1911

' 8 SHEETS-SHEET 1 I W @Jvfucwto'c P. RQ FORMAN. GUSHIONING MECHANISM FOR DOOR OPERATING DEVICES.

' PrLIOATIOH FIELED APILQ. 1908. 1,001,943., Patented Aug. 29, 1911.

a sauna-unfit 2.

, PQR. FORMAN; 5 OUSHIONING MECHANISM FOR DOOR OPERATING DEVICES.

APPLICATION FILED APB'21 1808.

3 SHEETS-SHEET 3.

Patented Aug. 29,1911.

UNITED "STATES PATENT OFFICE.

ARIS R. FORMAN, OF CHICAGO, ILLINOIS, ASBIGNOB, BY MESNE ASSIGNMENTS, TO

NATIONAL PNEUMATIC COMPANY, A CORPORATION OF WEST VIRGINIA.

CUSHIONING MECHANISM FOR DOOR-OPERATING DEVICES.

Specification of Letters latent.

application filed April 2, 1908.

Patented Aug. 29, .1911. Serial I l-72k To all whom it may concern:

Be it known that I, PA-ms R. FORMAN, a citizen of the United States, residing at Chicago, county of Cook, State of Illinois, have made a certain new and useful Invention in Cushioning lVlechanism for Door- Operating Devices, of which the following is a specification.

The invention relates to cushioning 1ncchanism for pneumatic operating devices.

The object of the invention is to provide means which are simple and eflieient for effecting quick starting and slow or cush ioned final movements of a door or other closure.

A further object is to provide power mechanism for opening and closing doors and means for efliciently cushioning the final movement of the door without depend ing upon any throttling operation a valve.

Other "objects of theinvention will appear more fully hereinafter.

The invention consists substantially in the construction, combination, location and relative arrangement of parts, all as will be more fully hereinafter-set forth, as shown in the accompanying drawings, and finally pointed out in the appended claims.

Referring tothe accompanying drawings,

and to the various views and reference signs a pearing thereonr-Figure 1 is a. .view in e ovation, parts broken off, showing a door and power actuated means for moving the door, with means embraced withinthe scope of my intention -for securing a cushioning of 1 the doormovement as the door appro'aohes the 'limitof 'such-nmvement; Figs. 2 andZ-l are enlarged detail views, somewhat diagrammatic, showing a valve construction "foi controlhng the supply and exhaust of operating medium to and from the power -mech -anism, and suitable for use in accomplishing-the objects and purposes of my invention. Fig. 4 is a view similar to Fig. 1.

the-door .and connections thereto from th" powet mechanism being omitted and show- Fig.1. s a. view' in topfp lan of the construetron shown in Fig. 4. and showing diagrammatieitlly an arrangement ofvalve suitable fora-rec in connection with the modified armngementof cushioning means. -'Fi'g. this 'a wile W in side elev l longitiidinal section, showing xipoWe'r cylinder'andthe relation thin, partsrbrokeavnut reference sign wherever itoccurs throughout p the several views.

In the operation of doors and similar closurcs and other devices, and especially where power operated means are employed to etlcct the door or closure movements, it is desirable that the movement of the door from its completely open position, in closing, or from its completely closed position, in opening, be initiated quickly, and that, as the door or other device approaches the limit of: its movement, whether in opening or closing, it will be cushioned. \Vhere pressure operated UHF-1111841111, emplo ed to effect the operation of the door, the cushioning effect is ordinarily accomplished by restricting the exhaust of the operating medium from the power cylinder as-thc door valve. by the operation of which the .areaof exhaust opening may be variedby closing or opening. more or less, the size of the exha-ust ports.

in accordance with the principles of my invention I propose to accomplish the .desired objects without. depending upon or using the valve to vary or control the size or area of the eihaust ports, and in carrying out my invent ion I employ a tank reservoir or receptacle which for brevity, and also to indicate breadth and scope I will hereinafter refer to as an expansion chain her, into which the operating medium, after having accomplished its work in the power cylinder. is permitted to flow-when the exhaust port. from the-power cylinder is opened. whereby thecxhaust prcssure'is reduced by expanding. into the expansion chamber.- [provide the expansion chamber" with restricted,openingto the atmosphere,

this manner I avoid entirelythe necessitv of relying on a valve to vary or'control the by thei expanded exhaust pressure "medium may gradually escape. I '-;1-1t) area of an exhaust port in order to secure the desired c'ushioning effect as the door nears the end of its movement Referring to the accompanying drawings, reference sign it designates a door or other closure to be moved; I) a rocking lever having connection with the door to move the same; D, a power cylinder to which an operating medium, sue-n as eompresstul an", is supplied to operate a piston 1, see [fig 6, within said cylinder; (1, is the piston rod which is connected to the door operating lever B for rocking the same. To operate the piston and rod'(), an operating medium,

in this instance compressed air, is admitted to and exhausted from ,theresp'ective ends of the cylinder. The supply and exhaust ot' the operating medium to and from the cylinder 1), is controlled by a valve F, see Figs. 2 and 3, operating in a casmgl), see

Fig. '1. The valve 1*, which is placed in the casing l, operates over a seat plate G, through which are formed the port openings ('3, T, 8 and 9, the valve F, controlling said openings. The pressure medium is supplied to the casing E through port 6.

The ports 8 and 9 respectively communicate through pipes {50, 31 with opposite ends of the cylinder I), and the port 7, is for the exhaust from the cylinder. The pressure supply pipe 10, communicates with a convenient source of pressure supply and delivers into casing l), throughfthe port 6. The exhaust pipe 11, is in communication with the exhaust port 7. The valve F is. provided with a recess 12. on the face thereof which bears against the seat plate Ur, as indicated in dotted lines in l igs. 2 and 3 and \vhich'recess is arranged and designed to establish communication between exhaust port 7, and one orthe other cylinder ports 2) or S), as the case may be, according to the angular pqsition intowhich the valve F, may be moved. As shown in 2, the valve F occupies a position to uncover port 8 to'tlie' supply port (3, and to'bring ports 7 and 9 into communication with each other, whereby the pressure medium is' admitted to one end of the cylinder,D, from supply. pipe 10, through port 6, into cas ng E, and

thence through port S,Iwhil e at the same time the other end of theeylinder is opened; 'to exhaust through port. 9,,the recess 12 exhaust port 7, and pipe 11'. In Fig.3, the

valve F, is shown in position to uncover ports l) and (3, and to bring ports 7 and 8 into' communication \vitheach other, thereby a d mitting the pressure medium through supso'ply pipe 10 into chamla-r E, through/port 6,

and thence"through port to that end of the cylinder with'which the said port 9 con'm-n[ni -ates, while at' the same time the opposite end of the cylinder is opened to exhaust through port- 8,- recess 12, port 7 and 'exhaustpipe 11. The valve F, may be shifted to eli'ect the above described 0 eration in any suitable manner. I have siown the stem of the valve extending through the casing l", and to which stem an operating rod may be attached, seeFig. 1.

The parts so far described may be of the usual or any well known construction andarrangement and in the speciticdetails thereof are not ofuny invention.

As above explained, when the valve F is moved into the position shown in Fig. 2 or that shown in Fig. 3, then one endof the cylinder is freely open to the pressure supply, while the other end of the cylinder is open to exhaust.

Under these conditions the door or other device to be moved will begin its movement rapidly, which movement would continue to the tail end of the travel of the door,. .theiteby causing an ob 'jcctionable slam and jar when the door reaches the end of its traveh'unlesS some means are provided for cushioning the final movement thereof. In order to avoid this slam and jar, and to providemeans for cushioning the final movement of the door and without employing the valve to efi'ect,

a partial closing or throttling of the area of. the exhaust port, l propose, in accord-.

anee with the principles of my invention, and asabove indicated, to provide a chamher ,into which the exhaust pressure from the dxhausting end of the cylinder may expand, but from which chamber the pressure may escape slowly to the outer air.

This may be accomplished in many different ways, as, for instance, by permitting the exhaust air to expand into a pipe, tank, res ervoir, or the like, indicated at 4, to which the exhaust pipe 11. delivers, andwhich expansion chamber 4, is provided with a small opening 14, to the htmosphere- --\'Vith this arrangement it will be readily seen; that when the valve 11, is shifted into position to admit the pressure medium' to one end of the cylinder, the other end of the cylinder is opened to the expansion chamber and thence, through the restricted openinglt, to the atmosphere. The exhaust air-from the exhausting end {of the cylinder is" thus porn-titted to expand into the larger area a fi't-irdet'lby the expansion chamber, there-.

by so reducing the pressure thereof as to arable the supply pressure in Itheother'end of the cylinder to initiate a quick movement of the door. Asthe door continues its movement, however, the travel of the piston in the cylinder iyduc'es thespaceoccupied by the exhaust air, and since the final escape of the exhaust air is retarded by having to pass't-hrough the restricted area of the opening 1.4, in chamber 4, the pressure which-is.

imposed upon the-exhaust air contained in i the expansion chamber 4, thelpipe 11-, and, the exhausting end of the cylinder T). hi creases-by'th: movement of-the piston Ward the exhausting end of the cylinder" thereby producing the desired cushioning e.t feet as the door apprm hesthe limit of its travel, the eol'itil'iued escape of the exhaust air from the expansion chamber through the small opening 14, enabling the piston of, the power cylinder to complete its stroke, but at a reduced rate of eed. It is obvious that the faster the power cylinder piston, and hence, also, the door, may try to move, under the influence of the live pressure supplied to the ope 'ating end of the cylinder, the greater will be the compression of the exhaust air in the expansion chamber, and hence, the; greater will be the resistance to the movement of the piston and door.

.liy the arrm'igement above described I am enabled to secure a quick starting movement of the door, and a gradually increasng cushioned effect, and without the use of any moving valve or other device to secure a choking or throttling of the path of the exhaust pressm'e.

It may sometimes be desirable to quickly reverse the movement of the door before the exhaustair has had sufiicient time to escape from the expansion chamber and the exhaust pipe 11, and the exhausting end of the power cylinder- I), and. hence when the reverse movement of the door commences the expansion chamber 4-, and pipe connec tion Ill, are already full of air under a greater or less degree of compression, and therefore in place of a free and quick start ing moverncnt' of the door, the door would have a slow sluggish moven'lent at the start which will continue in this condition throughout the extent of such movement. In order to obviate this, a separate expansion chamber may be provided for each end of the power cylinder, and a separate exhaust pipe leading to each expansion chamber. Such an arrangement is shown in Figs. 4 and 5. In this case the valve 15, is l'n'ovidcd with two recesses or ducts 1.6, 17, in its bearing face, and separated from each other by the interrmrdiate wall 18. The valve cooperates with a seat 19, in which are provided the pressure supply port '20,

the ports zl, 22, respectively col'nmunlcating with opposite ends ot the power cylinder 1), and also two exhaust ports 23, 24, re-

spectively connnunicating with the cxpan smn chambers 25, 26, each of said cl'ian'lbers having a restricted opening to the atmosphere, as indicated at 27, and similar to the opening H, in expansion chamber 4, above described with reference to the arrangement shown in Fig. 1, and having a similar function. The recess 16, in the valve 19, is of suflicicnt length to bring the cylinder port 21 into comumnlcatlon with exhaust port 23, and similarly, the recess 17, ill the valve is of sufficient length to bring the cylinder port 22, and the exhaust port Qatinto communication with each other, when the valve is suitably actuated. Thus it will be seen that instead of the exhaust from both ends of the cylinder being made through a common connection and into an expansion chamber common to both, separate exhaust connection, and a separate expansion chamber is provided for each end of the cylinder. With this arrangement it will be readily seenthatwhile the door is moving in one direction there will be ample time for a complete exhaust of the air from that end of. the cylinder where the cushioning effect is secured should the n'iovement ot' the door be reversed, and hence I am enabled to secure a quick starting and a slow or cushioned final movement of the door Having now set forth the object and nafure of my invention, and constructions embodying the principles thereof, what I claim as new and useful and of my own in vention, and desire to secure by Letters Pat ent is:

1. In a cushioning mechanism for door operating devices, a power cylinder, a piston operating therein, door moving devlces operated by the piston supply and exhaust ports for the power cylinder, and a valve for controlling said ports, in combination with an expansion chamber communicating with an exhaust port, and having an opening of restricted area to the atmos here.

2. ,In an apparatus of the class escribed, a power cylinder, supply and exhaust ports therefor, and a valve for opening and closing said ports, and means into which the exhaust from one end of the cylinder is permitted to expand, when pressure is supplied to the other end of said cylinder, said means having a restricted path to the atmoshcrc, whereby the movement inaugurated by the power cylinder is initially rapid, and finally cushioned.

3. In an apymratus of the class described, a power cylinder, supply and exhaust ports for each end thereof, and a valve for controlling said ports, in combination with an expansion chamber asstmiated with each exhaust port and having a restrictcdopening to the atlnospl-zcre.

In testimony whereof I have hereunto set my hand in the presence of thcsubscribing witnesses, on this twenty-fourth day 0 March A. D., 1908. h

PARTS R. FORMAN.

W'itncsses v Aumlrr 'l". l).-\'ncn n, M. II. MARTIN. 

